Photographic filter and antihalation layers



Feb. 20, 1962 A. OSSENBRUNNER ETAL 3,022,171

PHOTOGRAPHIC FILTER AND ANTIHALATION LAYERS Filed July 16, 1957 Light Sensitive Layer ;-Support Antihalation Layer comprising as Binding Agent a Polycarbonate INVENTORS ARM/N OSSENBRUNNER HELFR/ED KLOCKGETHER MZ ZQ Z THE /R A TTORNEYSA United States Patent Ofifi ce 3,922,??2 Patented Feb. 20, 1962 3,022,171 PHQTOGRAPHIC FILTER AND ANTIHALATION LAYERS Armin Ossenbrunner and Helfn'ed Klockgether, Leverkusen, Germany, assignors to Agfa Alrtiengesellschaft Filed July 16, 1957, Ser. No. 672,199 Claims priority, application Germany July 26, 1956 i (Jlaims. (1. 96-84) The present invention relates to light-absorbing photographic layers and more particularly to antihalation and filter layers for light sensitive photographic materials comprising silver halide emulsion layers.

It is known to provide photographic materials, such as black-and-white films and multi-layer color films, with an antihalation layer so as to avoid the formation of halation. This antihalation layer is arranged either between layers or on the back of the support. The antihalation layer generally consists of an antihalation dye which is removed in the photographic processing baths, and a binding agent, generally gelatine or, because of their better mechanical properties, alkali-soluble plastics.

The following are known examples of such plastics:

Copolymers of styrene and acrylic acid, vinyl isobutyl ether and maleic acid, vinyl butyl ether and maleic acid, and styrene and maleic acid, according to US. patent specification No. 2,077,789;

Condensation products of phenoxyacetic acid and form aldehyde, according to US patent specifications Nos. 2,075,145; 2,089,764 and 2,282,890;

Copolymers of acrylonitrile, vinyl butyl ether and maleic acid semi-esters, according to US. application Serial No. 622,088, filed November 14, 1956, now US. Patent 2,913,351, granted November 17, 1959 (Belgian Patent No. 552,893);

Cellulose acetate phthalates, polyvinyl phthalates according to US. patent specification No. 2,131,747.

In actual fact, however, the standards required of an antihalation layer are so high that only a few of the aforementioned binding agents can be considered for practical use in the manufacturing processes. In addition, recent for the support for which the existing dye carriers are not always the best possible. When a suitable synthetic resin is chosen as a binding agent for the antihalation layer the following requirements should be fulfilled:

1) Suflicient solubility in organic solvents which are at the same time solvents for the antihalation dye, and which should cause no or only slight swelling of the layer support, since if swelling does occur the support becomes colored.

(2) Sufficient solubility in the developers, which are often only weakly alkaline, so that no residues remain after processing.

(3) The smallest possible tendency to transfer to the emulsion layer disposed in contact with the antihalation layer. Any such transfer makes the film material unsuitable for use.

It is these last two requirements which are difi'icult to fulfill. An increase in the groups in the molecule which produce alkali solubility improves the solubility in the alkaline developers, but reduces the resistance to transfer due to the resulting more hydrophilic properties, while on the other hand a reduction in the groups producing alkali solubility improves the resistance to transfer, but reduces the solubility in the photographic baths.

It has now been found that antihalation layers can be produced which have excellent properties if high molecular alkali-soluble polycarbonic acid esters of aliphatic, cycloaliphatic, araliphatic and/or aromatic dihydroxy compounds containing acid groups, optionally in admixture with organic dihydroxy compounds Without acid groups are used as binding agents. These polycarbonic acid esters contain recurring units of the formula:

in which R stands for a bivalent organic radical containing as sole reactive group an acid group, such as at least one carboxylic and/or sulphonic acid group, whereby in part of these recurring units R may stand for a bivalent organic radical containing no acid groups or other reactive groups, said bivalent organic radical being derived from the aforementioned organic dihydroxy compounds by subtraction of the hydroxy groups. In case part of said recurring units contain no acid groups, these are present in such molar proportion that the polycarbonate does not lose its solubility in aqueous alkaline solution, these molar proportions being about 1-70 molar percent as calculated on the total molar weight of recurring units. As represented in the above formula these polycarbonic acid esters are linear.

The alkali-soluble polycarbonic acid esters of high molecular weight which are to be used in accordance with the invention can be obtained by reacting aliphatic, cycloaliphatic, araliphatic or aromatic dihydroxy compounds containing acid groups, if desired admixed with cycloaliphatic, araliphatic or aromatic dihydroxy compounds without acid groups, with carbonic acid chlorides such as bis-halogen, carbonic acid esters of dihydroxy compounds or with phosgene, for example according to the prescription given in German application F13,040 (now German Patent 971,790) or Belgian Patent 532,543. Such polycarbonates canthus contain the radicals of dihydroxy carboxylic acids such as tartaric acid, dihydroxy stearic acids, 2,5-dihydroxycyclohexane carboxylic acid, 4,4-dihydroxydicyclohexyl carboxylic acid-(2.2), 1,5-dihydroxy benzoic acid, 3,6-dihydroxybenzene-1,2-dicarboxy1ic acid, 4,4'-dihydroxydiphenyl-2,2-dicarboxylic acid and especially di-(monohydroxy aryl)alkanes containing carboxyl groups, such as 4,4'-dihydroxy-3,3'-dicarb0xy diphenylmethane and 4,4'-dihydroxy-3,3-dicarboxy-5,5'-dimethyl diphenyl methane, and also dihydroxysulphonic acids such as 1,4-dihydroxybenzene sulphonic acid-(2), 1,6-dihydroxynaphthalene sulphonic acid-(3) and 4,4'-dihydroxy diphenyl disulphouic acid-(2,2'), or 2,2[4,4-dihydroXy-diphenylene disulphonic acid (3,3)] propane. Particularly suitable for the process of the invention are those polycarbonic acid esters, for the production of which 4,4-dihydroxy-3,3-dicarboxy diphenyl methane or 4,4-dihydroxy 3,3 dicarboxy 5,5 dimethyl diphenyl methane have been used.

Other dihydroxy compounds which in addition may be used, if desired, for the production of the polycarbonates are:

As aliphatic dihydroxy compoundsethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, thiodiglycol, ethylene dithiodiglycol, the diand polyglycols produced from propyleneoxide-LZ, o, m, or p- Xylene glycol, propanedioll,3, butanediol-l,3, butanediol- 1,4, 2-methylpropanediol-l,3, pentanediol-l,5, Z-ethylpropanediol-L3, hexanediol-L6, octanediol-i,8, l-ethylhexanediol-1,3, and decanediol-1,l0,

As cycloaliphatic dihydroxy compoundscyclohexanediol-1,4, cyclohexanediol-LZ, 2,2-(4,4'-dihydroxy-dicyclohexylene)-propane and 2,6-dihydroxydecahydronaphthalene,

As aromatic dihydroxy compoundshydroquinone, resorcinol, pyrocatechol, 4,4'-dihydro:-;ydiphenyl, 2,2-dihydroxydiphenyl, 1,4-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6 dihydroxynaphthalene, 1,2 dihydroxynaphthalene, LS-dihydroxynaphthalene, dihydroxyanthraphenylene sulphone, 4,4

' 2,2-(4,4'-dihydroxy 3 methyl 1,1 (4,4' di'nydroxy cene, 2,2-dihydroxydinaphthyl-l,1 and o, m, p-hydroxybenzylalcoholi Preferred classes of aromatic dihydroxy compounds are the di-monohydroxy arylene sulphones and particularly the di-monohydroxy arylene alkanes, such as 4,4-di.- hydroxy-diphenylene sulphone, 2,2'-dihydroxydiphenylene sulphone, 3,3'-dihydroxydiphenylene sulphone, 4,4'-dihydroxy-Z,2,-dimethyl-diphenylene sulphone, 4,4'-dihydroxy- 3,3'-dimethyl-diphenylene sulphone, 2,2-dihydroxy-4,4'- dimethyl-diphenylene sulphone, 4,4-dihydroxy-2,2 '-diethyldiphenylene sulphone, 4,4 dihydroxy 3,3 diethyldidihydroxy-2,2'-di-tert.butyl-diphenylene sulphone, 4,4 dihydroxy-S,3-di-tert.butyl-diphenylene sulphone and 2,2-dihydroxy-l,l'-dinaphthylene sulphone, 4,4'-dihydroxy-diphenylene-methane,

,1 (4,4'-dihydroxyadiphenylene) -ethane,

,l-(4,4'-dihydroxy-diphenylene)-pr0pane 1- (4,4f-dihydroxysdiphenylene) -butane,

,1-(4,4-dihydroxy-diphenylene) -2-methyl-propane,

1,1- (4,4'-dihydroxy-diphenylene) -heptane,

'1, 1- (4,4'-dihydroxydiphenylene) -1-phenyl-methane,

(4,4'dihydroxy diphenylene) (4 methane,

(4,4 dihydroxy diphenylene) (4 ethyl phenyl'ene)- methane,

(4,41-'-dflaydroxy-diphenylene)-(4 isopropyl phenylene)- methane,

(4,4 dihydroxy diphenylene)-(4 butyl methane,

( 4,4-dihydroxy-diphenylene) -benzyl-methane,

-(4,4edihydroxy-diphenylene) -a-furyl-methane,

2,2-(4,4-dihydroxy-diphenylene)-propane,

2,2-;(4,4-dihydroxy-diphenylene)ebutane,

2,2-;(4,4 dihydroxy-diphenylene) pentane (melting point 2,2- (4,4'-dihyclroxy-diphenylene) -4- methyl-p entane,

2,2-(4,4'-dh1ydroXy-diphenylene)-heptane (boiling point 198-200 C. under 9.3 mms. mercury gauge),

2,2-(4,4'-dihydroxy-diphenylene)-octane,

2,2-(4, -dihydroxy-diphenylene)-nonane (melting point 1,1-(4,4' -dihydroxy-diphcnylene) 1 -phenylethane,

'(4,4-dihydroxy-dipheny1ene) -1- (a-furyl) -.ethane,

phenylene) 3,3-(4,4'1dihydroxy-diphenylene)-pentane,,

4,4- (4,4-dihydroxydiphenylene) -heptane, 1 1- 4,4-'-dihydroXy-diphenylene) -.cyclopentane, 1,1 (4,4-dihydroXy-diphenyleue)-cyclohexane,

- methyl phenylene)- 2,2 (4,4 -dihydroxy-diphenylene)sdecahydronaphthalene V (melting point 181" C.), 2,2-(4-,4- -.dihydroxy 3,3 dicyclohexyldiphenylene)- propane (melting point 144-146 (3.),

diphenylene) -propane (melting point 114 '0), 2,2- (5 ,5 'dihyd1'oxy-3-isopropyl-diphenylene) -butane, 1,1-(4,4-dihydroxy 3,37 dimethyl-diphenylene)-cyclohexane, 2,2- (4,4-dihydroxy-3,3 -dibuty1-diphenylene) propane, 2,2- (4,4-dihydroxy-3,3-diphenyl-diphenylene) -propane, 2,2-(4,4-dihydroxy-2,2-dimethyl-diphenylene)-propane, 1,1 (4,4-dihydroxy-3,3'-dimethyl-6,6-dibutyl-diphenylene)-'butane,

- di-tert.butyl-diphenylene)-ethane, 1,1-(4,4-dihydroxy 3,3 phenylene)-propane, 1,1 (4,4' dihydroxy 3,3

diphenylene) -butane,

- dimethyl-6,6-di-tert.butyl-didimethyl-6,6'-di-tert.butyl 3,3 dimethyl-6,6'-di-tert.butyldiphenylene) -isobutane,

1,1 (4,4-dihydroxy-3,3'-dimethy1 6,6 di tert.butyldiphenylene)-heptane, 1,1 (4,4-dihydroxy 3,3 dimethyl 6,6 di-tert.butyldiphenylene l-phenyl-methane,

hexylamine, and pyridine,

1,1 (4,4 dihydroxy 3,3 dimethy1-6,6'-di-tert.butyldiphenylene) -2-methyl-pentane,

1,1 (4,4 dihydroxy 3,3 dimethyl-6,6'-di-tert.butyldiphenylene)-2-ethyl-hexane, and

1,1 (4,4' dihydroxy 3,3 dimethyl-,6'-ditert.amyl

diphenylene) -butane,

2,2-(4,4'-dihydroxy-dinaphthylene)propane and 1,1e(4,4'-dihydroxy-dinaphthylene)-cyclohexane.

Among the great number of suitable di-monohydroxy arylene alkanes the 4,4'-dihydroxy-diphenylene alkanes are preferred, especially the 2,2-(4,4-dihydroxy-diphenylone-propane and the 1,1 (4,4 dihydroxy-diphenyiene)- cyclohexane.

The polycarbonates can be produced for example by introducing .phosgene into solutions, of dihydroxy compounds or of mixtures of the aforesaid dihydroxy compounds in organic bases, such as dimethylaniline, diethylaniline, trimethylamine, and pyridine, or in 'indifierent organic solvents, such as petrol, ligroin, cyclohexane, methylcyclohexane, benzene, toluene, xylene, chloroform, .methylenechloride, carbon tetrachloride, trichloroethylone, 'dichloroethane, methacetate, and ethylacetate, with addition of an acid-binding agent, e.g. tertiary amines.

A process particularly suitable bonates consists in introducing phcsgene into the aqueous solution or suspension or salts, such as lithium, sodium, potassium, and calcium salts of the dihydroztyv compounds, preferably in the presence of an excess of a base, such as lithium, sodiunn potassium, and calcium hydroxide or carbonate. The polycarbonate then precipitates out from the aqueous solution.

The conversion in the aqueous solution is promoted by the addition of solvents of the kind mentioned above which are inert to the reaction and capable of dissolving phosgene and eventually the produced polycarbonate.

The reaction conditions should preferably be so that one mole of the phosgene reacts with one mole of the dihydroxy compounds. Suitable temperatures are from about 0 C. to C.

' It is also possible to react the dihydroxy compounds containing acid groups, if desired in admixture with other dihydroxy compounds, with his chlorocarbonio solvents.

When using phosgene or bis-chlorocarbonic acid esters .as derivatives of the carbonic acid in producing polcarbonates catalysts also may be advantageous. Such catalysts are for instance tertiary or quaternary organic bases or salts thereof, such as trimethylamine, triethyldimethylcycloamine, dimethylamline, diethylaniline,

or for instance the corresponding hydrochlorides, and tetramethylammoniumliydroxide, triethyloctadecylammoniumchloride, dimethyl benzylphenylammonium-chloride, trimethylcyclohexylammoniumbromide, and N-methylpyridiniurnchloride, in amounts from about 0.05 to about 5 percent by Weight. These compounds maybe added to the reaction mixture before or during the reaction. 7

Furthermore in some of these cases it is preferable to add surface active agents, such as alkali metal salts of higher fatty acids or of sulphonic acids of higher aliphatic or of aromatic hydrocarbons and polyoxyethylated alcohols and phenols. Greater amounts of the alkali or alkaline earth metal for producing polycarquaternary ammonium bases mentioned above, too, act

as such surface active agents.

In the production of polycarbonates according to the various processes it further is advantageous to employ small amounts of reducing agents, for example sodium or 1 aqueous alkalies such as sodium groups of the polycarbonates consisting of the chloro- 5 carbonic acid ester group and which terminate the chains, such as the phenols, for instance, phenol, tert. butylphenyl-, the cyclo-hexylphenyl-, and 2,2(4,4-dihdroxyphenylene-4'-methoxyphenylene) propane, aniline and methylaniline, it is possible to regulate the molecular weight of the polycarbonate-s in wide limits.

The working up of the reaction mixture may be effected when operating in the presence of acid-binding agents and organic solvents such as methylene chloride or benzene, in such a manner that the reaction mixture is dissolved cold in dilute sodium hydroxide solution, the organic layer separated, the aqueous layer filtered oil and the polycarbonate precipitated from the filtrate by acidification, or that the organic solvent is distilled oil from the reaction mixture upon acidification with dilute hydrochloric acid and the polycarbonate filtered off.

The new polycarbonates are soluble in addition to a number of organic solvents such as acetone, tetrahydrofurane, dioxane, dimethyl formamide, mixture of methanol and benzene or ethanol and benzene, further in or potassium hydroxide or sodium carbonate solution.

{The antihalation layers produced from the aforementioned polycarbonates and antihalation dyestuffs known as such are distinguished by sufficient solubility in alkaline silver halide developing solutions even if these are Weakly alkaline and contain considerable amounts of salts, furthermore by a good resistance to abrasion and to transfer to emulsions layer disposed in contact with said antihalation layer. The described antihalation layers may be produced on supports of cellulose ester's, such as cellulose acetate, cellulose acetobutyrate, nitrocellulose, polyesters of terephthalic acid and glycol, polyvinylchloride and copolymers of vinylchloride with maleic anhydride or maleic acid esters, polystyrene, and high molecular linear polycarbonates as disclosed for instance in Belgian Patent 532,543. The polycarbonates of the present invention may be applied in admixture with other synthetic or natural resins containing alkali-solubilizing groups, such as copolymers of styrene and acrylic acids, vinylisobutylether and maleic acid, acrylonitrile, vinylbutylether and maleic half esters, celluloseacetatephthalate, polyyinylphthalate. These resins may be combined with the polycarbonates containing alkali-solubilizing groups in the most varied proportions, it is preferred, however, if at least 50 percent of the binding agent consists of said poly carbonates.

The present invention is illustrated by the accompanying drawing representing a cross-section in enlarged scale through a photographic material according to the present invention.

. Example 1 8 g. of an antihalation dye, such as a dyestufi of the formula:

CH; CH; I

H005 01 JOOH 12 g. of a polycarbonic acid ester from 4,4-dihydroxy- '3,3-dicarboxydiphenyl methane with a K-value of 6 (the K value is defined in Cellulosechemie," 13, (1932), page 60), are dissolved in the following solvent mixture:

70 parts of ethanol 20 parts of ethyl acetate 10 parts of butanol The solution is applied by the clipping method to the back of an acetyl cellulose film and is dried at approximately C. by air blown thereon. Silver halide emulsions for the production of a multi-layer color photographic material are then applied to the front of the layer support by casting.

The layer dissolves satisfactorily on processing in the photographic baths and does not transfer to the emulsion layer under the conditions prevailing in practice, even with long storage.

The above polycarbonate is produced in the following manner:

Into a solution of 79 parts of 4,4'-dihydroxy-3,3-dimethyl-S,5'-dicarboxydiphenylene-methane, parts of pyridine and 600 parts of methylene chloride, there are introduced with stirring 24.6 parts of phosgenc at about 0 C. within 1 /2 hours. After stirring overnight at room temperature, the solution is treated with 50 parts of water, stirred for 2 minutes and after the addition of 450 parts of 2 N hydrochloric acid stirred for a further 15 minutes. Methylene chloride is subsequently distilled oil under vacuum with stirring and the residue is filtered off. The residue remaining after filtration is washed with Water until free from chlorine and dried under vacuum at 80 C.

Example 2 6 g. of an antihalation dye as for instance a dyestuff of the formula:

CH CH (I)H I H0O!) (EOOH O CzHs 10 parts of ethyl acetate 30 parts of isopropanol The coating is applied to a polycarbonate foil as disclosed in German application No. A 22,482 of Apr. 14, 1955 (now published as No. 1,001,586), and dried. The film is coated with a black-and-White negative emulsion. The properties of the antihalation layer conform to the requirements which have been stated.

The above polycarbonate bonding agent (K=10) is produced as follows:

To a mixture of 17.65 parts of 2,2(4,4'-dihydroxydiphenylene)-propane-bis-chlorocarbonic acid ester, 15.15 parts of 4,4 dihydroXy-3,3'-dicarboxy 5,5 dimethyldiphenylene-methane and 350 parts of methylene chloride there is added dropwise with stirring at about 0 C.

dilute hydrochloric acid and methylene chloride evapo rated with stirring in vacuo.

After filtration of the residue, the filter residue is washed first with hydrochloric acid and subsequently with water until no further chlorine is detectable in the wash water. The filter residue is dried at 80 C. under vacuo. Further dyestuiis which may be used ior the production of the antihalation layers are for instance those disclosed in British specifications 694,681 and 760,739.

Example 3 12 g. of an antihalation dye according to U.S. patent specification No. 2,282,890, Example 2-,

6 g. of a copolymer of styrene and maleic acid according to U.S. patent specification No. 2,077,789, and

6 g. of a polycarbonic acid' ester as referred to in 7 Example 2, are dissolved in the following solvent mixture:

30 parts of ethanol 30 parts of acetone 10 parts of ethyl acetate 30 parts of tetrachloroethane.

The solution is applied to the back of a foil of a polyester of terephthalic acid-and. glycol having layers of silver halide emulsion on the front.

Example 4 halide emulsion layer is then applied to the front of the V support. The properties of the antihalation layer conform to the requirements which have been stated.

The polycarbonate is obtained according to the process disclosed in Example 1, replacing the dihydroxy compound of'said example by an equimolecular amount of the dihydroxy compound disclosed in the preceding paragraph.

Example 5 I A solution of 4.7 g, of the dyestufi disclosed in Exarnple 2, 3 g. of a copolymer of an alkali-soluble copolymer of styrene and methacrylic acid according to U.S.

specification No. 2,077,789, 5.8 g. of a polycarbonate .of 3,6-dihydroxybenzene-dicarboxylic acid-1,2 in 70 g.

of isopropanol and 30 g. of ethanol is coated on the back of a nitrocellulose film support and dried. A silver halide emulsion layer is then applied to the front of the support. The antihalation layer meets all requirements.

The polycarbonate is obtained according to the process disclosed in Example l,'replacing the dihydroxy com pound of said example by an equimolecular amount of the dihydroxy compound disclosed in the preceding paragraph.

What we claim is:

l. A light-sensitive photographic material comprising a light transmitting support, a photographically lightsensitive silver halide gelatin layer coated on one side of said support and an alkali-soluble antihalation layer con taining a light absorbing antihalation dyestufi coated on the other side of said'support, said antihalation layer containing as a binding agent substantially a major proportion of a high molecular film-forming linear polycarbonic ester of at least one dihydroxy compound selected from the class consisting of aliphatic, cycloaliphatic, araliphatic and aromatic compounds having hydroxy groups selected from the class consisting of alcoholic and phenolic hydroxy groups, at least 30 molar percent of the dihydroxy compound units in the ester also containing from one to two acid groups selected from the class consisting of carboxyl and sulfonic acid groups to render the ester soluble in aqueous alkaline solutions.

2. A light-sensitive photographic material according to claim 1 wherein the ester is the polycarbonate of a dimono-hydroxy-aryl alkane containing carboxylic acid 7 groups.

3. The combination of claim 1 wherein the support is a film of high molecular weight linear unsubstituted polycarbonate. 7

4. The combination of claim 1' in which the support is a film of high molecular weight linear unsubstituted polycarbonate, and the alkaline soluble polycarbonate is a carboxylated polycarbonate of a ibis-parahydroxy phenyl alkane.

5. The combination of claim 1 in which the dinydroxy compound is bis-(4hydroxy-3-carboxy phenyl) methane- 6. In combination, a photographically sensitive silver halide emulsion layer on a support, and an antihalo stratum on saidsupport in antihalation relationship with said silver halide emulsion layer, said stratum having a light-absorbing material distributed in a bonding material, at least half of said bonding material being a high molecular weight film-forming linear polycarbonate of at least one dihydroxy compound selected from the class consisting of aliphatic, cycloaliphatic, araliphatic and aromatic compounds having hydroxy groups selected from the class consisting of alcoholic and phenolic hy-- droxy groups, at least 30 molarpercent of the dihydroxy compound units in the polycarbonate also containing from one to two acid groups selected from the class consisting of carboxyl andsulfonic acid groups to render the polycarbonate soluble inaqueous alkaline solutions, any remaining bonding material beingv an alkali-soluble resin selected from the class consisting. of cellulose acetate phthalate, polyvinyl phthalate, and copolymers of styrene ,with acrylic acids, styrene with maleic acid, vinyl isobutyl ether with maleic acid, and acrylonitrile with vinyl-butyl ether and maleic acid half esters; 7

7. The combination of claim 6 whereinfthe bonding material is a mixture of a polyvinyl phthalate bonding agent and a polycarbonate of both bis (4-hydroxy-3-carboxy-S-methyl phenyl) methane and 2,2-bis,(parahydr0xy phenyl) propane. Y

8. The combination of claim 6 wherein the bonding material is a mixture'of (I) a bonding copolymer of styrene with maleic acid and (II) a polycarbonate of both bis-(4-hydroxy-3-carboxy-5-methylphenyl) methane and 2,2-bis (parahydroxy phenyl) propane.

9. The combination of claim 6 wherein the bonding material is a mixture of (1) acopolymerof acrylonitrile, vinyl 'butyl ether, and maleic acid monoethyl ester and (II) a polycarbonate of 2,2'-dicarboxy-4,4'-dihydroxy-dicyclohexyl.

10. The combination of. claim 6'wherein the bonding" rnatenal is a mixture of (I) a bonding copolymer of styrene with methacrylic acid and (Ii) a polycarbonate of 3,G-dihydrQXybenZene-dicarboxylic acid-1,2.

References Cited in the file of this patent UNITED STATES PATENTS Belgium Oct. 30, 1954 

1. A LIGHT-SENSITIVE PHOTOGRAPHICH MATERIAL COMPRISING A LIGHT TRANSIMITTING SUPPORT, A PHOTOGRAPHICALLY LIGHT SENSITIVE SILVER HALIDE GELATIN LAYR COATED ON ONE SIDE OF SAID SUPPORT AND AN ALKALI-SOLUBLE ANTIHALAT ON LAYER CONTAINING A LIGHT ABSORBING ANTIHALATION DYESTUFF COATED ON THE OTHER SIDE OF SAID SUPPORT, SAID ANTIHALATION LAYER CONTAINING AS A BINDING AGENT SUBSTANTIALLY A MAJOR PROPORTION OF A HIGH MOLECULAR FILM-FORMING LINEAR POLYCARBONIC ESTER OF AT LEAST ONE DIHYDROXY COMPOUND SELECTED FROM THE CLASS CONSISTING OF ALIPHATIC, CYCLOALIPHATIC, ARALIPHATIC AND AROMATIC COMPOUNDS HAVING HYDROXY GROUPS SELECTED FROM THE CLASS CONSISTING OF ALCOHOLIC AND PHENOLIC HYDROXY GROUPS, AT LEAST 30 MOLAR PERCENT OF THE DIHYDROXY COMPOUND UNITS IN THE ESTER ALSO CONTAINING FROM ONE TO TWO ACID GROUPS SELECTED FROM THE CLASS CONSISTING OF CARBOXYL AND SULFONIC ACID GROUPS TO RENDER THE ESTER SOLUBLE IN AQUEOUS ALKALINE SOLUTIONS. 